Process of cracking tar and bituminous schist oils with recovery of by-products



Jan. 14, 1936. L. BouLANGER Er Al. K 2,027,464

PROCESS 0F CRACKING TAR AND YBI'I'UNIINOUS SCHIST OILS WITH RECOVERY 0F BY-PRODUCTS Filed Jan. l0, 1934 YPatented Jan. 14, 1936 UNITED STATES PATENT OFFICE PROCESS OF CRACKING TAB AND BITUMI- NOUS SCHIST OILS WITH RECOVERY F BY-PRODUCTS Louis Boulanger, Brussels, and Ferdinand Emsens, Lommel, Belgi Application January 10, 1934, Serial No. 700,118

. In Great Britain August 4, 1933 2 Claims. (Cl. ISB-61) particularly applicable to the primary oils oi low temperature distillation of coal. A further object oi this invention is to eiect the recovery of the by-products, namely colorless benzol.

According to this invention, the primary oils, or the tar oils, or the bituminous schist oils,VV are rst oxidized, by means of a current of diluted ozone, after which they are washed with limewater and treated in a hydro-extractor for dehydration. This process of washing the oils avoids the use of acid and the subsequent neutralization which gave uncertain results. The tar or oil is then introduced into a retort i (provided with stirrers and baiiies) in which the oil is made to boil; the vapor of the tar or oils are overheated at a temperature over 800 C., thereby producing the cracking. The vapors thus decomposed are forced through the first of a series oi three receptacles, 3; wherein a first reddish liquid, containing the major portion of the phenols is condensed; the vapors which have not been condensed are led into a second receptacle 4 wherein they are thoroughly stirred by a mixture of ozone and nitrogen monoxide. 'By this special treatment the sulfur compounds are transformed into soluble sulpha s. the remainingphenols are reduced into b ols, and there is production of ammonia. 'l'.he resultant compounds are subjected in receptacle 0 to the absorption action of a solution oi lime water containing magnesia and theammonia may be absorbed in a solution of diluted sulphuric acid.

The. vapors then pass through a rectier 'l conf taining a solution of potassium hydroxide which absorbs phenols which may still have been carried on, and are led into arefrigerator -where the benzol is condensed and collected through a slphon.

Y The apparatus for carrying out the process according to this invention is illustrated more or less schematically in the appended drawing, wherein certain parts are in section.

i designates a retort into which the oils and/or tar to be cracked are introduced, after they have been, as above stated, treated by diluted ozone,

in the proportion of about 20 gr. oi ozone for each ton (metric) oi tar, then washed by lime-water and dried in a hydro-extractor.

The bottom oi the retort is heated as illustrated and the hot gases travel between the double-walls 2 of the retort, not only to vaporize the tar or oils in the bottom portion of the retort. but also to overheat the vapors ot the tar or oils in the top portion of the retort. This overheating reaches 800 C. and more and produces the cracking of the vapors. The retort may be provided inside with stirrers, Scrapers and baiiles which are not illustrated, as being known per se. The vapors coming out of the retort are led into the receptacle 3 wherein the major portion of the phenols are condensed and therefore separated: the vapors are then led into an aluminum sphere I, with double walls between which vacuum is produced. In this sphere the vapors, consisting oi a mixturel of benzol, mercaptans and other sulfur compounds, are thoroughly mixed by jets of a mixture of ozone and nitrogen monoxide. This mixture o! ozone and nitrogen monoxide is supplied under a pressure o! 'for instance four atmospheres by a pipe '5. 'I'he mercaptans and other: sulnde compounds are decomposed, -the phenols are reduced and transformed into benzol and thevmixture ot these' products passes into the receptacle .6 which contains lime-water and magnesio for retaining compounds of the charactor of the oxides oi sulfur. From receptacle 6v the vapors, which contain almost exclusively benzol, pass in a further receptacle 'I through a solution ot potassium hydroxide which iixes the last traces of phenols which can still be carried away in the benzol. The receptacle 1 is preferably placed in a water-bath containing calcium chloride and maintained by ebullition at a temperature oi 105 C. which maintains the vapors of benzol at a temperature of about 80 to 90 C. and allows same to pass but condenses any other vapors. The benzol now rid o1' the last traces o f phenol and other products is nally condensed in acoii condenser I0 and is collected at. Il through a siphon which is not illustrated. The benzol thus obtained, is perfectly white and odorless.

Having now fully described our said invention, what we claim and desireto secure by letters Patent, is:v

nous schist oils, which consists in 4oxidizing the oils by diluted ozone, washing said oils in'limewater and treating same inra dehydrator, vaporizing said oils in e. retort and superheating the resulting vapors at a temperature above 800'* C.,

condensing the major portion of the phenols from the vapors, mixing the vapors thoroughly with ozone and nitrogen monoxide, leading said vapors into lime-water and magnesia. thence through a solution of potassium hydroxide to retain the remaining phenols, and collecting the benzol by condensation.

3. An apparatus for cracking hydro-carbon pressure a mixture o! ozone and nitrogen monoxoils comprising a retort, a partial condenser conide within the inner walls into the central space nected by pipe line to the said retort a double of said sphere. wall sphere adapted to have a vacuum main- LOUIS BOULANGER. tained between the double wells attached to said FERDINAND EMSENS.

i partial condenser and mams tor injecting under 

